Randomised controlled trial comparing the effect of brimonidine and timolol on visual field loss after acute primary angle closure.

AIM: To compare the effect of brimonidine and timolol in reducing visual field loss in patients with acute primary angle closure (APAC). METHODS: In addition to standard acute medical treatment, patients presenting with APAC were randomised to either brimonidine 0.2% or timolol 0.5% upon diagnosis, then twice daily for 4 weeks. After laser peripheral iridotomy (LPI), subjects underwent three baseline perimetry tests during the first week, and then at weeks 4, 8, 12, and 16. Pointwise linear regression analysis was applied to the field series of each of these subjects starting with the third test (total of five tests per subject). Progression was defined as a significant regression slope (p<0.05) showing 1 dB per year or more of sensitivity loss at the same test location in the series. Patients were also compared for prevalence of abnormal fields at 16 weeks, which was defined as an abnormal glaucoma hemifield test result and/or corrected pattern standard deviation outside the 95% confidence limits. RESULTS: 59 subjects (31 in the brimonidine group; 28 in the timolol group) completed the study. There were 47 females (79.7%), the majority of subjects (94.9%) were Chinese and the mean age was 59.2 (SD 7.2) years. There were no significant differences between the two groups with respect to demographic features, presenting intraocular pressure (IOP), duration of symptoms, time from presentation to LPI, or mean IOP at each study visit. Over the 16 week study period, despite adequate statistical power, no difference was found between groups in terms of the number of patients with progressing locations, the mean number of progressing locations per subject, or the mean slope of the progressing locations. Nine (29%) subjects in the brimonidine group and 10 (35.7%) in the timolol group were found to have significant visual field defects at 16 weeks (p = 0.58). 15 out of these 19 subjects (78.9%) already had these visual field defects in the first week. CONCLUSIONS: In the first 16 weeks after APAC, there was no difference in the prevalence of visual field defects or rate of visual field progression between brimonidine and timolol treated groups.

Direct thermal desorption-gas chromatography and gas chromatography-mass spectrometry profiling of hop (Humulus lupulus L.) essential oils in support of varietal characterization.

The use of direct thermal desorption-gas chromatography-mass spectrometry (DTD-GC-MS) and DTD-GC-flame ionization detection (DTD-GC-FID) for characterization of hop essential oils is described. Four hop varieties (Nugget, Galena, Willamette, and Cluster) from the Yakima valley (Yakima, WA) 1998 harvest were analyzed by DTD-GC-MS and DTD-GC-FID methodology. Approximately 1 g of hops was needed for the analysis. Hop samples were prepared for GC-MS and/or GC-FID profiling in approximately 20 min. More than 100 volatile compounds have been identified and quantified for each hop variety. The results were found to be in good agreement with conventional steam distillation-extraction (SDE) data. A calibration curve for determination of essential oil content in hops by DTD-GC-FID has been generated. Quantitation of hop oil content by DTD-GC-FID was shown to be in good agreement with conventional SDE data. The recovery of key oil components valuable for varietal identification was demonstrated to be highly reproducible and characteristic of each variety analyzed when DTD-GC-FID was used for analysis.

What is the role of botulinum toxin in the treatment of dysthyroid strabismus?

BACKGROUND: Botulinum toxin A has been used in the treatment of dysthyroid strabismus primarily as a temporary measure during the active phase of the disease. We report on our experience with 65 patients. METHOD: We review the records of 65 patients with dysthyroid strabismus who were treated with botulinum toxin A at Moorfields Eye Hospital between 1984 and 1996. CONCLUSIONS: Patients with a short duration of relatively mild dysthyroid strabismus have a chance of long-term benefit with botulinum toxin A. There is little use for botulinum toxin A in cases of severe dysthyroid disease.

Ocular motility disturbances after surgery for retinal detachment.

PURPOSE: Relatively little has been published on the management of motility problems after surgery for retinal detachment. We report a large series with the aim of describing clinical features, management, and outcome. METHODS: The charts of 68 of 86 consecutive patients referred to one of us between 1989 and 1995 were retrieved and analyzed. Sixty-two had unilateral and 6 bilateral surgery for retinal detachment. In 45 cases the macula was detached at surgery. The visual acuity of the affected eyes ranged from hand motions to 6/6. Sensory testing suggested potential binocular function in 39.7%. Fifty-nine patients had combined vertical and horizontal strabismus, 8 horizontal alone, and 1 vertical only. The average vertical deviation measured 10.2 PD and the average horizontal 19 PD. RESULTS: Twelve patients underwent strabismus surgery, 26 were treated with botulinum toxin, 21 were managed conservatively with prisms or occlusion, and 8 refused or did not require treatment. Forty-seven percent of the group regained binocularity (20.5% cured with surgery or botulinum toxin, 26.5% controlled with prisms or intermittent injection with botulinum toxin). A total of 20.7% gained improvement in appearance, 19.1% were managed with permanent occlusion, and 13.2% either refused or did not require treatment. CONCLUSION: Macula off retinal detachment, poor visual acuity plus or minus distortion, and multiple procedures for retinal reattachment are associated with a poor prognosis for restoration of binocular vision and a good outcome. In our hands, botulinum toxin treatment is the method of choice, with surgery used in selected cases.

Combination cyclopentolate and phenylephrine for mydriasis in premature infants with heavily pigmented irides.

PURPOSE: This study examined whether safe and effective mydriasis can be achieved in premature infants with heavily pigmented irides using combination cyclopentolate 0.2% and phenylephrine 1% eyedrops. METHODS: A prospective, randomized double-blind study was performed to compare combination cyclopentolate 0.2% and phenylephrine 1% eye-drops with triple instillation of tropicamide 0.5% and phenylephrine 2.5%. Twenty-eight consecutive babies with dark irides and birthweight <1600 g referred for screening for retinopathy of prematurity comprised the study population. Infants' eyes were randomly dilated twice with both regimens within a 2-week period. Blood pressure, heart rate, and pupil size were measured. RESULTS: Good mydriasis was achieved in both groups with no significant differences in pupil size or blood pressure (systolic, diastolic, or mean arterial pressures) over starting baseline values. Pulse rates decelerated below the baseline values in both groups, but these differences were not large. CONCLUSION: The single combination eyedrop of cyclopentolate 0.2% and phenylephrine 1% is as effective and safe a mydriatic for infants with dark irides as both tropicamide 0.5% and phenylephrine 2.5%.

Susceptibility status of Aedes albopictus to three topically applied adulticides.

The baseline susceptibility of Aedes albopictus (Sabah strain) to malathion was determined. Both laboratory-colonized and field-collected Ae. albopictus at Harris County, TX are resistant to malathion but susceptible to Scourge. The acute toxicity of bendiocarb to Ae. albopictus is confounded by its rapid knockdown and delayed recovery syndrome of poisoning.

Magnetic resonance imaging of brain metastases: magnetisation transfer or triple dose gadolinium?

Magnetic resonance (MR) imaging of brain metastases relies on the neovascularity of metastases and the associated breach of blood-brain barrier manifesting as enhancement on T1-weighted images. There are 2 main strategies to improve the detection of brain metastases. One may increase the dose of gadolinium and increase the signal of the lesion. Alternatively, one may also lower the signal of the background (by magnetisation transfer suppression), in which case the enhancing lesion is rendered more conspicuous without increasing the dose of gadolinium. We aim to compare the efficacy of single-dose conventional spin-echo T1 scans with magnetisation transfer (MT) suppression with triple-dose conventional spin-echo T1 scans in the detection of brain metastases in 18 patients undergoing imaging for brain metastases. An incremental dose technique was employed. After administration of a single dose of gadolinium, MT suppressed T1-weighted scans were obtained, followed by a conventional T1 scan. Two doses of gadolinium were subsequently given, achieving a cumulative triple-dose, and a conventional T1-weighted scan was then performed. We found single-dose MT suppressed and triple-dose scans performed equally well and detected 26 metastatic lesions. They detected 5 (5/26, 19%) more lesions than the conventional single-dose T1 scans. Five (5/21, 24%) questionable lesions on single-dose conventional scans were confidently diagnosed on the single-dose MT suppressed and the triple-dose conventional scan. We conclude that single-dose MT suppressed scans are a cost-effective technique of detecting brain metastases.

Sub-Tenon's versus retrobulbar anesthesia for cataract surgery.

BACKGROUND AND OBJECTIVE: A prospective, randomized, double-blind study was conducted to compare sub-Tenon's anesthesia with retrobulbar anesthesia. PATIENTS AND METHODS: One hundred six patients undergoing cataract extraction received either sub-Tenon's anesthesia (55 patients) or retrobulbar anesthesia (51 patients). The number of injections required, time until adequate akinesia was achieved, degree of pain experienced, and complications of the anesthetic injection were compared. The depth of the akinesia after sub-Tenon's injection was graded. RESULTS: There was no significant difference between the two study groups with respect to time of onset of adequate akinesia, the need for a second top-up injection, and the effectiveness of the akinesia. The sub-Tenon's injection group reported less pain during the anesthetic injection, as well as during the postoperative injection of subconjunctival gentamicin. CONCLUSION: Sub-Tenon's anesthesia is a safe technique that is comparable to retrobulbar anesthesia.

Tuberculosis of the chest wall: unusual presentation as a breast lump.

A 33-year-old woman presented with a painless right breast lump of four weeks' duration. There were no symptoms such as fever or night sweats. Mammogram revealed an elliptical lesion in the retromammary region. Ultrasonography showed a hypoechoeic collection deep in the right breast. As the lesion was localised to the chest wall, computed tomography of the thorax was performed. This confirmed a fluid collection in the right anterior chest wall and also bilateral upper lobe consolidations, suggestive of pulmonary tuberculosis with an abscess in the anterior chest wall. Ultrasound-guided core needle biopsy confirmed a Mycobacterium tuberculosis infection. It is unusual for a tuberculous abscess of the chest wall to present as a painless breast lump. We also present a companion case of tuberculous mastitis to illustrate their distinct imaging features.